A heat exchanger comprising a tube bundle and at least one tubular header, of the kind mentioned above, may typically be used as a condenser arranged to form part of an air conditioning installation for a motor vehicle. A refrigerant fluid flows through the condenser; and such a condenser is provided with corrugated spacers which define cooling fins between the tubes. The tubes are brazed to one or more headers. In this connection the tubes may have a hairpin or double pass configuration, so that they are connected to a single header; alternatively the tubes may be straight, with the heat exchanger then having two headers, one at each end of the tube bundle.
The support member in the assembly may for example be part of the bodywork of the motor vehicle. Alternatively it may be part of some piece of equipment, which may for example be another heat exchanger.
It is known to fasten the condenser of an air conditioning installation on to another heat exchanger, for example the cooling radiator of the engine of the vehicle, in such a way that a common airstream can flow in succession through the engine cooling radiator and the condenser.
It is known from the specification of Japanese patent No. 64-38481 to secure a heat exchanger of the kind described above by means of U-shaped collars, in either one or two parts, which are nested around a tubular header of the heat exchanger, to which they are secured by means of fixing screws. A disadvantage of this arrangement is that the structure of the tube bundle has to be modified, and the assembly operations are complicated.
It is also known from the specification of European patent application EP 0 440 400 to provide fastening lugs which are welded on to the tubular header. This arrangement is again unsatisfactory, given that in the event of rupture of one of the fastening lugs, the whole assembly comprising the heat exchanger and its fastening lugs has to be replaced.